In certain parallel processing systems containing a plurality of data processing nodes, one or more switch units are provided for transferring data between the data processing nodes. A switch unit receives a connection request from one of a plurality of nodes and establishes a link between the data processing node which sends the connection request, and another of the plurality of data processing nodes, which is requested by the connection request. As used herein, a “switch node” means any node of the plurality of data processing nodes which is capable of connecting to such a switch unit. A switch node includes a device driver and at least one adapter.
More particularly, described herein is a control technique for a switch node having multiple adapters. Advantageously, multiple adapters are assumed to write data faster than a single adapter. However, it is recognized herein that a need exists in the art for a control technique for enhancing the process of switching between adapters during the writing of messages. The present invention provides such a selection control technique.